Is Zinc Good for Colds?
Quick Answer
Yes, if taken within 24 hours of symptom onset. Zinc lozenges can reduce cold duration by 1-3 days and severity by about 30%. The key: start immediately and use high-dose lozenges (75mg+ daily) that slowly dissolve. After 24-48 hours, it doesn't help much. Doesn't prevent colds, just shortens them.
Key Points
- Start within 24 hours of symptom onset
- Lozenges work better than pills
- 75mg+ daily in divided doses
- Reduces duration by 1-3 days
- Doesn't prevent colds or help after 48 hours
Detailed Answer
Zinc for colds is one of the better-supported supplement uses, but the details matter.
What research shows:
• Meta-analysis (2017, 7 trials): Zinc reduced cold duration by 33% • Cochrane Review: High-dose zinc lozenges shorten colds by 1-3 days • Must start within 24 hours of first symptoms • Works better for adults than children
Why lozenges specifically:
The mechanism appears to be local. Zinc ions interfere with rhinovirus replication in the throat. Pills that you swallow don't work as well. Nasal sprays are risky (can damage smell). Lozenges that dissolve slowly are ideal.
The right protocol:
• Zinc acetate or gluconate lozenges (13-25mg each) • One lozenge every 2-3 hours while awake • Total: 75mg+ elemental zinc daily • Start at FIRST symptoms, not day 3 • Continue for duration of cold (not beyond)
What zinc doesn't do:
• Prevent colds (regular supplementation doesn't reduce frequency) • Help after 48 hours of symptoms • Work for flu or COVID (different viruses)
Evidence Quality
Multiple high-quality studies support this
Key Sources:
- reviewZinc for Common Cold: Meta-Analysis (2017)
- reviewCochrane Review: Zinc for Cold Treatment
- studyZinc Lozenge Efficacy and Dosing Study
Related Questions
Common reasons: started too late (need within 24 hours), used pills instead of lozenges, dose too low, or it was the flu (zinc doesn't help flu). Timing is critical.
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About this information: Our recommendations draw from peer-reviewed clinical trials, systematic reviews, and the same medical databases your doctor uses. These statements have not been evaluated by the FDA. Supplements are not intended to diagnose, treat, cure, or prevent any disease.
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